Pipeline handoff validator

Pipeline Handoff Validator

Overview

Validates artifacts at pipeline boundaries before they are consumed by the next phase. Catches incomplete specs, ambiguous acceptance criteria, and plan defects before they propagate through the pipeline and compound into larger failures.

Core principle: Artifacts at pipeline boundaries are contracts. Unvalidated contracts produce downstream failures that are harder to diagnose than the original defect.

Announce: "I'm using the pipeline-handoff-validator to check this artifact before proceeding."

The Contract Rule

EVERY ARTIFACT CROSSING A PIPELINE BOUNDARY IS VALIDATED AGAINST ITS CONTRACT.
GAPS FOUND HERE COST MINUTES. GAPS FOUND DOWNSTREAM COST HOURS.

When to Use

graph TD
    A{"Artifact handoff\nbetween skills?"} -->|yes| B{"Which boundary?"}
    A -->|no| C["Not in scope"]
    B -->|"Design spec → Plan"| D["Mode A:\nSpec Validation"]
    B -->|"Plan → Execution"| E["Mode B:\nPlan Validation"]

Invoked automatically by build-feature between macro-phases. Invoked manually when using pipeline skills individually (e.g., running plan-writing on a spec produced in a previous session).

---

Mode A: Design Spec → Plan-Writing Validation

Validates a design spec before plan-writing consumes it.

Input: Path to design spec document (typically docs/specs/YYYY-MM-DD-<topic>-design.md)

Contract checks:

#	Check	What it validates	Pass condition
A1	Structure	Spec follows skills/brainstorming/references/design-spec-template.md	All required sections present: Problem Statement, Success Criteria, Scope Boundaries, Selected Approach, Acceptance Criteria, Risk Register
A2	Testable criteria	Every acceptance criterion has a verification method	Each criterion contains a concrete assertion (not vague goals like "should be fast")
A3	Scope boundaries	Always/Ask First/Never table is defined	Table exists with at least 1 entry in each column
A4	Risk coverage	Selected approach has documented risks	At least 1 risk with likelihood, impact, and mitigation
A5	Assumptions resolved	No critical unverified assumptions	Zero assumptions marked "Unverified" that gate a design decision
A6	Approach clarity	Selected approach has sufficient detail for decomposition	Approach section contains specific technology choices, not abstract patterns

Procedure:

1. Read the design spec file
2. Parse sections against the template structure
3. Run each contract check
4. Produce the Handoff Compliance Table (see output format below)
5. If any check is GAP: present gaps with specific remediation suggestions
6. If all checks PASS: confirm the artifact is ready for plan-writing

---

Mode B: Plan → Plan-Execution Validation

Validates a plan document before plan-execution consumes it.

Input: Path to plan document (typically .plan/plan-{YYYYMMDD}-{slug}.md)

Contract checks:

#	Check	What it validates	Pass condition
B1	Structure	Plan follows skills/plan-writing/references/plan-document-template.md	All required sections present: Metadata, Requirements, File Structure, Tasks, DAG, Waves
B2	Quality score	Plan passed adversarial verification	Plan Quality Score documented and >= 90
B3	Rollback blocks	Every task has a rollback strategy	Each task contains a rollback block with specific commands
B4	DAG integrity	No circular dependencies	Mermaid graph parseable, no cycles in dependency chain
B5	File structure	Lock-In table present	File Structure Lock-In table exists with Action column (CREATE/MODIFY)
B6	Zero placeholders	No placeholder patterns in code blocks	Scan all code blocks against skills/plan-writing/references/placeholder-detector-rules.md patterns: zero matches
B7	Requirements traced	Every requirement maps to at least one task	Traceability matrix present with R(N) → T(M) mappings, no orphans

Procedure:

1. Read the plan document file
2. Parse sections against the template structure
3. Run each contract check
4. For B6 (placeholder scan): extract all fenced code blocks, match against patterns from skills/plan-writing/references/placeholder-detector-rules.md
5. Produce the Handoff Compliance Table
6. If any check is GAP: present gaps with specific remediation suggestions
7. If all checks PASS: confirm the artifact is ready for plan-execution

---

Output Format

Both modes produce a Handoff Compliance Table displayed to the user:

## Handoff Compliance — [Mode A: Spec / Mode B: Plan]

**Artifact:** `<file path>`
**Validated:** <timestamp>

| # | Check | Result | Detail |
|---|-------|--------|--------|
| A1/B1 | Structure | PASS/GAP | [missing sections or "all sections present"] |
| A2/B2 | ... | PASS/GAP | [specific evidence] |
| ... |

**Verdict:** READY / GAPS FOUND (N gaps)

If gaps are found, each gap includes:

• Which section or field is missing/incomplete
• What the contract requires
• Suggested fix (specific, actionable)

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Integration with build-feature

The build-feature skill invokes this validator automatically:

1. After Macro-Phase 1 (brainstorming) completes → Mode A validates the design spec
2. After Macro-Phase 2 (plan-writing) completes → Mode B validates the plan

If the validator reports gaps:

• Present the Handoff Compliance Table to the user
• Offer: "Fix these gaps before proceeding, or proceed with known gaps?"
• If the user chooses to fix: return to the preceding skill phase
• If the user chooses to proceed: log acknowledged gaps in the pipeline state

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Red Flags — STOP and Investigate

• Skipping validation "because the spec/plan looks complete"
• Marking a GAP as PASS because "it's close enough"
• Proceeding to the next phase without showing the Compliance Table
• Validating from memory instead of reading the actual artifact file
• Reporting READY without checking every contract item

---

Common Rationalizations

Excuse	Reality
"The spec was just written, it's fine"	Freshness does not equal completeness. Validate.
"Plan-writing will catch any issues"	Plan-writing assumes valid input. Garbage in, garbage out.
"This is a simple feature, validation is overkill"	Simple features with unclear acceptance criteria produce the most rework.
"I can see the spec has all sections"	Seeing sections is not the same as verifying their content. Read them.
"The user already approved the spec at GATE 4"	User approval validates direction. Contract validation checks completeness. Different concerns.
"Validation slows down the pipeline"	Catching gaps here takes minutes. Catching them during execution takes hours.